scholarly journals ANALISIS KEBOCORAN & KEBAKARAN TANGKI BLENDING BAHAN BAKAR MIGAS

2021 ◽  
Vol 1 (3) ◽  
pp. 39-47
Author(s):  
Sulistiana Agung Riyanto ◽  
Vidya Rina Wulandari ◽  
Bagas Putra Arfyansyah
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Corrosion Products ◽  
Uniform Corrosion ◽  
Tank Wall ◽  
Corrosive Environment ◽  
Joint Area ◽  
Long Time ◽  
Type Fuel

Explosions and fires that occurred in the blending/mixing tanks of fuel with naphtha to produce pertalite type fuel were initiated by a leak in the tank wall. Based on the results of observations, inspections and tests that have been carried out, the leak of the tank which is the cause of the explosion and fire is the result of the reaction of the tank wall in the weld joint area with base metal (HAZ) which is susceptible to corrosion with acidic tank fluid contents (pH- 5) so as to form an acidic and corrosive environment in the tank with the formation of H2S as a corrosion initiator, reinforced by the discovery of corrosion products in the form of MnS, FeS2, and FeS compounds, elements (S), and the appearance of fractography in the form of white dots indicating uniform corrosion if it occurs for a long time can erode the tank wall and form a leak hole.

scholarly journals Experimental Analysis of Reinforcement Rust in Cement under Corrosive Environment

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 241
Author(s):  
Xiaozhen Li ◽  
Hui Wang ◽  
Jianmin Wang ◽  
Junzhe Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Steel Corrosion ◽  
Corrosion Products ◽  
Chloride Salt ◽  
Corrosive Environment ◽  
Cement Slurry ◽  
Passivation Film ◽  
Chloride Environment ◽  
Corrosive Environments ◽  
Structural Layer

In this work, the microstructure characteristics of corrosion products of reinforcement under a corrosive environment with chloride, carbonation and the combination of chloride-carbonization were studied by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy/energy spectroscopy (SEM-EDX). The results indicate that the outside of the passivation film reacts with the cement slurry to produce Fe–SiO4 in all three corrosive environments. The inner side is not completely corroded. The morphology of the corrosion is different in the three environments. In a chloride environment, corrosion products have obvious cracks, and the local layered structure is dense. In a carbonation environment, the surface of the steel corrosion shows a uniform granular structure and loose texture. With the combination of chloride and combination, the surface of the structural layer of steel corrosion was uneven and accompanied by protrusions, cracking and spalling occurred. The composition of the corrosion substances in the three corrosion environments are mainly composed of FeO, Fe3O4, Fe2O3 and Fe–SiO4. The content of iron oxide increases from a chloride salt, carbonization to the composite environment, indicating that the corrosion degree intensifies successively.

Hydrides Effect on the SCC Initiation on Zircaloy-4 Claddings

2007 ◽  
Vol 23 ◽  
pp. 249-252
Author(s):  
Alice Dinu ◽  
M. Radulescu ◽  
D. Ionescu ◽  
Silviu Florea
Keyword(s):  
Radial Direction ◽  
Zirconium Hydride ◽  
Simultaneous Action ◽  
Thermal Treatments ◽  
Corrosive Environment ◽  
Metallographic Method ◽  
Before And After ◽  
Cause Of Failure ◽  
Different Content ◽  
Type Fuel

The main cause of failure of CANDU-type fuel bundles during their operation is the Stress Corrosion Cracking (SCC). This mechanism appears in presence of the simultaneous action of a corrosive agent and of mechanical stress. The presence of precipitated zirconium hydride platelets can affect the propagation of the SCC cracks. For this reason, we studied the influence of content of hydrogen on the initiation and the propagation of SCC crack. To do this study, some Crings samples with different content of hydrogen (100-500ppm) were exposed in a corrosive environment containing iodine (10-4g/cm2) at 320°C. The stress state, the concentration of the corrosive environment and the temperature were maintained constant. For comparison, in the same conditions some as-received samples were exposed. To relieve the morphology of the precipitates of the zirconium hydride the samples were been investigated using metallographic method, before and after thermal treatments. While before the experiment a circumferential orientation of the hydrides precipitates was observed, after the thermal treatments a reorientation of hydrides in a radial direction was been remarked. Investigation by SEM method revealed the propagation modes of cracks in the case of the as-received samples and it was put in evidence the existence of the microcracks on the inner surface of tested samples.

A Review of Alloy 600 Cracking in Operating Nuclear Plants Including Alloy 82 and 182 Weld Behavior

2004 ◽  
Author(s):  
Warren Bamford ◽  
John Hall
Keyword(s):  
Weld Metal ◽  
Base Metal ◽  
Steam Generator ◽  
Structural Integrity ◽  
Reactor Vessel ◽  
Alloy 600 ◽  
Control Rod ◽  
Nuclear Plants ◽  
Steam Generator Tubing ◽  
Long Time

Service induced cracking in Alloy 600 has been known for a long time, having been first observed in the 1980’s in steam generator tubing and small bore piping, and later, in 1991, in reactor vessel control rod drive mechanism (CRDM) head penetrations. Other than steam generator tubing, which cracked within a few years of operation, the first Alloy 600 cracking was in base metal of Combustion Engineering small bore piping, followed closely by CE pressurizer heater sleeves. The first reactor vessel CRDM penetrations (base metal) to crack were in France, US plants found CRDM cracking several years later. Three plants have discovered weld metal cracking at the outlet nozzle to pipe weld region. This was the first known weld metal cracking. This paper will chronicle the development of service-induced cracking in these components, and compare the behavior of welds as opposed to base metal, from the standpoint of time to crack initiation, growth rate of cracks, and their impact on structural integrity. In addition, a discussion of potential future trends will be provided.

Dechlorination of large marine iron artifact using a novel technique involving impressed current

2015 ◽  
Vol 62 (4) ◽  
pp. 259-269
Author(s):  
Georgios Batis ◽  
Angeliki Zacharopoulou ◽  
Evgenia Zacharopoulou ◽  
Helene Siova ◽  
Vasilike Argyropoulos
Keyword(s):  
Organic Coating ◽  
Corrosion Products ◽  
Alkaline Solutions ◽  
Content Type ◽  
Conservation Treatment ◽  
Chemical Reagents ◽  
Before And After ◽  
Long Time ◽  
Electrochemical Chloride Extraction ◽  
Short Time

Purpose – This paper aims to develop an electrochemical dechlorination method for large objects in a short time, which were for a long time in the sea. Traditionally, in conservation, chlorides are extracted from marine iron artifacts using complete immersion of those objects in alkaline solutions with or without electrolysis. However, these techniques are time-consuming and very costly, especially when applied to large marine artifacts such as cannons and anchors. Design/methodology/approach – An appropriate sponge was chosen based on resistance to NaOH and the rate of exacted chlorides. Application of electrochemical dechlorination in situ and removal of chloride were measured by the scanning electron microscope (SEM)-EDAX method on the corrosion products and by titration of the electrolysis solution. X-ray diffraction (XRD) method is used for identification of corrosion products before and after application of electrochemical chloride extraction. Findings – The electrochemical chloride extraction (ECE) method is applied against the corrosion of reinforced concrete. From the authors’ research, it is obvious that ECE can successfully extract chlorides from dried large metallic objects exported from the sea. The method of ECE removes the majority of chlorides from the metal during conservation treatment so that the application of organic coating will allow the object to remain stable over a long period. Originality/value – A new methodology was developed for dechlorination of metallic objects exported from the sea in a short time and thus the consumption of chemical reagents was cut down.

scholarly journals Low Cycle Fatigue Properties of Alloy 617 base Metal and Weld Joint at Room Temperature

2014 ◽  
Vol 3 ◽  
pp. 2201-2206 ◽  
Author(s):  
Seon-Jin Kim ◽  
Pil-Ho Choi ◽  
Rando Tungga Dewa ◽  
Woo-Gon Kim ◽  
Min-Hwan Kim
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Alloy 617

Combined in situ micro-XRF, LIBS and SEM-EDS analysis of base metal and corrosion products for Islamic copper alloyed artefacts from Umm Qais museum, Jordan

2013 ◽  
Vol 14 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Abeer Arafat ◽  
Maram Na’es ◽  
Vicky Kantarelou ◽  
Naseem Haddad ◽  
Anastasia Giakoumaki ◽  
...  
Keyword(s):  
Base Metal ◽  
Corrosion Products ◽  
Eds Analysis ◽  
Umm Qais

A Case Study of a Cooling Pipe for a Pre-Cooler Used in a 70-MPa Hydrogen Station

2017 ◽  
Author(s):  
Saburo Okazaki ◽  
Hisao Matsunaga ◽  
Shigeru Hamada ◽  
Masami Nakamura ◽  
Hisatake Itoga ◽  
...  
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Hydrogen Gas ◽  
Nitrogen Gas ◽  
Mechanical Joint ◽  
Joint Specimen ◽  
Cooling Pipe ◽  
Round Bar ◽  
Hydrogen Station

A case study was conducted on the cooling pipe of a precooler which had been used in a 70-MPa hydrogen station demonstration project. The cooling pipe consisted of a main pipe, a mechanical joint pipe and a mechanical joint. The main and mechanical joint pipes had been joined using TIG welding. Through chemical composition analysis, microstructure observation and Vickers hardness measurement, it was revealed that the main and mechanical joint pipes had been manufactured from SUS316L and that 316L was the filler metal used for TIG welding. Round-bar specimens were machined out of the main pipe in order to investigate the tensile properties of the base metal. On the other hand, both round-bar specimen without reinforcement and square-bar specimens with reinforcement were fabricated from the weld-joint. Using the three types of specimens, slow strain rate tensile tests were performed in 0.1 MPa nitrogen gas and in 115 MPa hydrogen gas at a temperature of −40 °C. Reduction of area (RA), φ, for the round base-metal specimen, the round weld-joint specimen and the square weld-joint specimen were respectively, 83.5 %, 71.3 % and 81.4 % in nitrogen gas, whereas the related values in hydrogen gas were 60.1 %, 61.3 % and 40.1 %. In other words, the RA for the three types of specimens was smaller in hydrogen gas than in nitrogen gas. Dimples were formed on the fracture surfaces of the three specimen types in nitrogen gas, whereas both dimples and quasi-cleavages were formed in hydrogen gas.

Low Cycle Fatigue Properties of 316LN Stainless Steel Welded by GTAW in Nitrogen Added Environment

2007 ◽  
Vol 345-346 ◽  
pp. 275-278
Author(s):  
Dae Whan Kim ◽  
Chang Hee Han ◽  
Woo Seog Ryu
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Yield Strength ◽  
Base Metal ◽  
Weld Joint ◽  
Low Cycle Fatigue ◽  
Ferrite Content ◽  
Fatigue Properties ◽  
316Ln Stainless Steel ◽  
Type 316Ln Stainless Steel

Tensile and fatigue properties were evaluated for base and welded type 316LN stainless steel. Welding methods were GTAW (308L, Ar environment) and GTAWN (316L, Ar + N2 environment). Yield strength of weld joint was higher than that of base metal but elongation of weld joint was lower than that of base metal. UTS of weld joint was slightly lower than that of base metal. Yield strength and elongation with welding method were almost same. Fatigue life of weld joint was lower than that of base metal but fatigue strength of weld joint was higher than that of base metal. Ferrite content was increased with welding. Fatigue life welded by GTAWN was better than that of GTAW at RT and 600°C. This fatigue life behavior was consistent with the behavior of ferrite content.

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